This application is written in response to PAR-10-126, Strategic Partnering to Evaluate of Cancer Signatures [SPECS II] (U01)." The proposed project focuses on translating our previously discovery-oriented gene expression signatures into laboratory tests for lymphoma clinical trials and patient care. Our research consortium, the Lymphoma and Leukemia Molecular Profiling Project (LLMPP) will design and validate a multi-analyte diagnostic and prognostic gene signature assay to differentiate the 5 most common aggressive B cell non-Hodgkin lymphomas. Each lymphoma subtype will then be further classified into prognostic groups. Three methods of gene expression profiling with demonstrated utility in our feasibility testing will be rigorously evaluated including high density oligonucleotide arrays (Affymetrix), direct multiplexed measurement of gene expression (Nanostring), and quantitative nuclease protection assay (High Throughput Genomics). In Phase 1 diagnostic genes will be tested at all 3 platforms will be compared simultaneously at the Patient Characterization Center (PCC) at NCI-Frederick, operated by SAIC-Frederick and a second academic study site. In Phase 2, the "winning" platform will be tested at the PCC and 2 additional sites. In Phase 2, tested genes will be expanded to include prognostic signatures. Data will be generated in such a way as to be appropriate for submission for regulatory review. As opposed to our previous discovery work that was performed with snap frozen tissues which are scare and only available at academic centers, this project will use formalin fixed, paraffin embedded tissues (FFPET), which are routinely available from all biopsies, in order to have the broadest clinical application. The LLMPP is uniquely posed to accomplish this work by virtue of having performed the "gold standard" GEP experiments that define the diagnostic and prognostic distinctions in these lymphomas as well as holding matching FFPET blocks from the same cases. Hence, this proposed research addresses a critical unmet need to translate previous advances in the molecular diagnosis of aggressive lymphomas into a new clinical paradigm for accurate diagnosis, prognosis, and therapeutic target identification.